re: call for testers - switching ofppc to xorg X11
matthew green <[email protected]> Mon, 13 Dec 2010 00:02:37 +1100
| Newsgroups | gmane.os.netbsd.ports.ofppc |
|---|---|
| Message-ID | <[email protected]> |
> matthew green wrote: > > > frank, could you explain what this patch is doing? or more exactly, > > why? what's with the AGP enablement? > > I'm not sure about the technical details, but I guess that you have to > switch the Marvell controller into AGP-mode to be able to access AGP-cards > on the PCI bus. The Pegasos2 has no real AGP bus, it is somehow... > emulated? > > By writing 0x08000000 to GT_GPP_Value_Set the configuration space of AGP > cards becomes visible. Writing the same value to GP_GPP_Value_Clear makes > them disappear again. > > The problem in the original source was that the AGP configuration space was > only enabled during autoconfig. So every PCI bus scan after that was unable > to see AGP cards. OK. is there a reason to swap it on and off just for pci conf reads? .mrg.